1219840720 has 80 divisors (see below), whose sum is σ = 3245685120. Its totient is φ = 417664512.

The previous prime is 1219840711. The next prime is 1219840723. The reversal of 1219840720 is 270489121.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×1219840720² = 2976022764340236800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1219840723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 816294 + ... + 817786.

It is an arithmetic number, because the mean of its divisors is an integer number (40571064).

Almost surely, 2^1219840720 is an apocalyptic number.

1219840720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1219840720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1622842560).

1219840720 is an abundant number, since it is smaller than the sum of its proper divisors (2025844400).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1219840720 is a wasteful number, since it uses less digits than its factorization.

1219840720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2972 (or 2966 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 34.

The square root of 1219840720 is about 34926.2182321533. The cubic root of 1219840720 is about 1068.4832266454.

The spelling of 1219840720 in words is "one billion, two hundred nineteen million, eight hundred forty thousand, seven hundred twenty".